/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000 Wim Taymans <wtay@chello.be>
* 2004 Wim Taymans <wim@fluendo.com>
*
* gstclock.c: Clock subsystem for maintaining time sync
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
/**
* SECTION:gstclock
* @title: GstClock
* @short_description: Abstract class for global clocks
* @see_also: #GstSystemClock, #GstPipeline
*
* GStreamer uses a global clock to synchronize the plugins in a pipeline.
* Different clock implementations are possible by implementing this abstract
* base class or, more conveniently, by subclassing #GstSystemClock.
*
* The #GstClock returns a monotonically increasing time with the method
* gst_clock_get_time(). Its accuracy and base time depend on the specific
* clock implementation but time is always expressed in nanoseconds. Since the
* baseline of the clock is undefined, the clock time returned is not
* meaningful in itself, what matters are the deltas between two clock times.
* The time returned by a clock is called the absolute time.
*
* The pipeline uses the clock to calculate the running time. Usually all
* renderers synchronize to the global clock using the buffer timestamps, the
* newsegment events and the element's base time, see #GstPipeline.
*
* A clock implementation can support periodic and single shot clock
* notifications both synchronous and asynchronous.
*
* One first needs to create a #GstClockID for the periodic or single shot
* notification using gst_clock_new_single_shot_id() or
* gst_clock_new_periodic_id().
*
* To perform a blocking wait for the specific time of the #GstClockID use the
* gst_clock_id_wait(). To receive a callback when the specific time is reached
* in the clock use gst_clock_id_wait_async(). Both these calls can be
* interrupted with the gst_clock_id_unschedule() call. If the blocking wait is
* unscheduled a return value of #GST_CLOCK_UNSCHEDULED is returned.
*
* Periodic callbacks scheduled async will be repeatedly called automatically
* until it is unscheduled. To schedule a sync periodic callback,
* gst_clock_id_wait() should be called repeatedly.
*
* The async callbacks can happen from any thread, either provided by the core
* or from a streaming thread. The application should be prepared for this.
*
* A #GstClockID that has been unscheduled cannot be used again for any wait
* operation, a new #GstClockID should be created and the old unscheduled one
* should be destroyed with gst_clock_id_unref().
*
* It is possible to perform a blocking wait on the same #GstClockID from
* multiple threads. However, registering the same #GstClockID for multiple
* async notifications is not possible, the callback will only be called for
* the thread registering the entry last.
*
* None of the wait operations unref the #GstClockID, the owner is responsible
* for unreffing the ids itself. This holds for both periodic and single shot
* notifications. The reason being that the owner of the #GstClockID has to
* keep a handle to the #GstClockID to unblock the wait on FLUSHING events or
* state changes and if the entry would be unreffed automatically, the handle
* might become invalid without any notification.
*
* These clock operations do not operate on the running time, so the callbacks
* will also occur when not in PLAYING state as if the clock just keeps on
* running. Some clocks however do not progress when the element that provided
* the clock is not PLAYING.
*
* When a clock has the #GST_CLOCK_FLAG_CAN_SET_MASTER flag set, it can be
* slaved to another #GstClock with the gst_clock_set_master(). The clock will
* then automatically be synchronized to this master clock by repeatedly
* sampling the master clock and the slave clock and recalibrating the slave
* clock with gst_clock_set_calibration(). This feature is mostly useful for
* plugins that have an internal clock but must operate with another clock
* selected by the #GstPipeline. They can track the offset and rate difference
* of their internal clock relative to the master clock by using the
* gst_clock_get_calibration() function.
*
* The master/slave synchronisation can be tuned with the #GstClock:timeout,
* #GstClock:window-size and #GstClock:window-threshold properties.
* The #GstClock:timeout property defines the interval to sample the master
* clock and run the calibration functions. #GstClock:window-size defines the
* number of samples to use when calibrating and #GstClock:window-threshold
* defines the minimum number of samples before the calibration is performed.
*/
#include "gst_private.h"
#include <time.h>
#include "gstclock.h"
#include "gstinfo.h"
#include "gstutils.h"
#include "glib-compat-private.h"
/* #define DEBUGGING_ENABLED */
#define DEFAULT_WINDOW_SIZE 32
#define DEFAULT_WINDOW_THRESHOLD 4
#define DEFAULT_TIMEOUT GST_SECOND / 10
enum
{
PROP_0,
PROP_WINDOW_SIZE,
PROP_WINDOW_THRESHOLD,
PROP_TIMEOUT
};
enum
{
SIGNAL_SYNCED,
SIGNAL_LAST
};
#define GST_CLOCK_SLAVE_LOCK(clock) g_mutex_lock (&GST_CLOCK_CAST (clock)->priv->slave_lock)
#define GST_CLOCK_SLAVE_UNLOCK(clock) g_mutex_unlock (&GST_CLOCK_CAST (clock)->priv->slave_lock)
struct _GstClockPrivate
{
GMutex slave_lock; /* order: SLAVE_LOCK, OBJECT_LOCK */
GCond sync_cond;
/* with LOCK */
GstClockTime internal_calibration;
GstClockTime external_calibration;
GstClockTime rate_numerator;
GstClockTime rate_denominator;
GstClockTime last_time;
/* with LOCK */
GstClockTime resolution;
/* for master/slave clocks */
GstClock *master;
/* with SLAVE_LOCK */
gboolean filling;
gint window_size;
gint window_threshold;
gint time_index;
GstClockTime timeout;
GstClockTime *times;
GstClockTime *times_temp;
GstClockID clockid;
gint pre_count;
gint post_count;
gboolean synced;
};
/* seqlocks */
#define read_seqbegin(clock) \
g_atomic_int_get (&clock->priv->post_count);
static inline gboolean
read_seqretry (GstClock * clock, gint seq)
{
/* no retry if the seqnum did not change */
if (G_LIKELY (seq == g_atomic_int_get (&clock->priv->pre_count)))
return FALSE;
/* wait for the writer to finish and retry */
GST_OBJECT_LOCK (clock);
GST_OBJECT_UNLOCK (clock);
return TRUE;
}
#define write_seqlock(clock) \
G_STMT_START { \
GST_OBJECT_LOCK (clock); \
g_atomic_int_inc (&clock->priv->pre_count); \
} G_STMT_END;
#define write_sequnlock(clock) \
G_STMT_START { \
g_atomic_int_inc (&clock->priv->post_count); \
GST_OBJECT_UNLOCK (clock); \
} G_STMT_END;
#ifndef GST_DISABLE_GST_DEBUG
static const gchar *
gst_clock_return_get_name (GstClockReturn ret)
{
switch (ret) {
case GST_CLOCK_OK:
return "ok";
case GST_CLOCK_EARLY:
return "early";
case GST_CLOCK_UNSCHEDULED:
return "unscheduled";
case GST_CLOCK_BUSY:
return "busy";
case GST_CLOCK_BADTIME:
return "bad-time";
case GST_CLOCK_ERROR:
return "error";
case GST_CLOCK_UNSUPPORTED:
return "unsupported";
case GST_CLOCK_DONE:
return "done";
default:
break;
}
return "unknown";
}
#endif /* GST_DISABLE_GST_DEBUG */
static void gst_clock_dispose (GObject * object);
static void gst_clock_finalize (GObject * object);
static void gst_clock_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec);
static void gst_clock_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec);
static guint gst_clock_signals[SIGNAL_LAST] = { 0 };
static GstClockID
gst_clock_entry_new (GstClock * clock, GstClockTime time,
GstClockTime interval, GstClockEntryType type)
{
GstClockEntry *entry;
entry = g_slice_new (GstClockEntry);
/* FIXME: add tracer hook for struct allocations such as clock entries */
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
"created entry %p, time %" GST_TIME_FORMAT, entry, GST_TIME_ARGS (time));
entry->refcount = 1;
entry->clock = clock;
entry->type = type;
entry->time = time;
entry->interval = interval;
entry->status = GST_CLOCK_OK;
entry->func = NULL;
entry->user_data = NULL;
entry->destroy_data = NULL;
entry->unscheduled = FALSE;
entry->woken_up = FALSE;
return (GstClockID) entry;
}
/* WARNING : Does not modify the refcount
* WARNING : Do not use if a pending clock operation is happening on that entry */
static gboolean
gst_clock_entry_reinit (GstClock * clock, GstClockEntry * entry,
GstClockTime time, GstClockTime interval, GstClockEntryType type)
{
g_return_val_if_fail (entry->status != GST_CLOCK_BUSY, FALSE);
g_return_val_if_fail (entry->clock == clock, FALSE);
entry->type = type;
entry->time = time;
entry->interval = interval;
entry->status = GST_CLOCK_OK;
entry->unscheduled = FALSE;
entry->woken_up = FALSE;
return TRUE;
}
/**
* gst_clock_single_shot_id_reinit:
* @clock: a #GstClock
* @id: a #GstClockID
* @time: The requested time.
*
* Reinitializes the provided single shot @id to the provided time. Does not
* modify the reference count.
*
* Returns: %TRUE if the GstClockID could be reinitialized to the provided
* @time, else %FALSE.
*/
gboolean
gst_clock_single_shot_id_reinit (GstClock * clock, GstClockID id,
GstClockTime time)
{
return gst_clock_entry_reinit (clock, (GstClockEntry *) id, time,
GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
}
/**
* gst_clock_periodic_id_reinit:
* @clock: a #GstClock
* @id: a #GstClockID
* @start_time: the requested start time
* @interval: the requested interval
*
* Reinitializes the provided periodic @id to the provided start time and
* interval. Does not modify the reference count.
*
* Returns: %TRUE if the GstClockID could be reinitialized to the provided
* @time, else %FALSE.
*/
gboolean
gst_clock_periodic_id_reinit (GstClock * clock, GstClockID id,
GstClockTime start_time, GstClockTime interval)
{
return gst_clock_entry_reinit (clock, (GstClockEntry *) id, start_time,
interval, GST_CLOCK_ENTRY_PERIODIC);
}
/**
* gst_clock_id_ref:
* @id: The #GstClockID to ref
*
* Increase the refcount of given @id.
*
* Returns: (transfer full): The same #GstClockID with increased refcount.
*
* MT safe.
*/
GstClockID
gst_clock_id_ref (GstClockID id)
{
g_return_val_if_fail (id != NULL, NULL);
g_atomic_int_inc (&((GstClockEntry *) id)->refcount);
return id;
}
static void
_gst_clock_id_free (GstClockID id)
{
GstClockEntry *entry;
g_return_if_fail (id != NULL);
GST_CAT_DEBUG (GST_CAT_CLOCK, "freed entry %p", id);
entry = (GstClockEntry *) id;
if (entry->destroy_data)
entry->destroy_data (entry->user_data);
/* FIXME: add tracer hook for struct allocations such as clock entries */
g_slice_free (GstClockEntry, id);
}
/**
* gst_clock_id_unref:
* @id: (transfer full): The #GstClockID to unref
*
* Unref given @id. When the refcount reaches 0 the
* #GstClockID will be freed.
*
* MT safe.
*/
void
gst_clock_id_unref (GstClockID id)
{
gint zero;
g_return_if_fail (id != NULL);
zero = g_atomic_int_dec_and_test (&((GstClockEntry *) id)->refcount);
/* if we ended up with the refcount at zero, free the id */
if (zero) {
_gst_clock_id_free (id);
}
}
/**
* gst_clock_new_single_shot_id:
* @clock: The #GstClockID to get a single shot notification from
* @time: the requested time
*
* Get a #GstClockID from @clock to trigger a single shot
* notification at the requested time. The single shot id should be
* unreffed after usage.
*
* Free-function: gst_clock_id_unref
*
* Returns: (transfer full): a #GstClockID that can be used to request the
* time notification.
*
* MT safe.
*/
GstClockID
gst_clock_new_single_shot_id (GstClock * clock, GstClockTime time)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
return gst_clock_entry_new (clock,
time, GST_CLOCK_TIME_NONE, GST_CLOCK_ENTRY_SINGLE);
}
/**
* gst_clock_new_periodic_id:
* @clock: The #GstClockID to get a periodic notification id from
* @start_time: the requested start time
* @interval: the requested interval
*
* Get an ID from @clock to trigger a periodic notification.
* The periodic notifications will start at time @start_time and
* will then be fired with the given @interval. @id should be unreffed
* after usage.
*
* Free-function: gst_clock_id_unref
*
* Returns: (transfer full): a #GstClockID that can be used to request the
* time notification.
*
* MT safe.
*/
GstClockID
gst_clock_new_periodic_id (GstClock * clock, GstClockTime start_time,
GstClockTime interval)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (start_time), NULL);
g_return_val_if_fail (interval != 0, NULL);
g_return_val_if_fail (GST_CLOCK_TIME_IS_VALID (interval), NULL);
return gst_clock_entry_new (clock,
start_time, interval, GST_CLOCK_ENTRY_PERIODIC);
}
/**
* gst_clock_id_compare_func:
* @id1: A #GstClockID
* @id2: A #GstClockID to compare with
*
* Compares the two #GstClockID instances. This function can be used
* as a GCompareFunc when sorting ids.
*
* Returns: negative value if a < b; zero if a = b; positive value if a > b
*
* MT safe.
*/
gint
gst_clock_id_compare_func (gconstpointer id1, gconstpointer id2)
{
GstClockEntry *entry1, *entry2;
entry1 = (GstClockEntry *) id1;
entry2 = (GstClockEntry *) id2;
if (GST_CLOCK_ENTRY_TIME (entry1) > GST_CLOCK_ENTRY_TIME (entry2)) {
return 1;
}
if (GST_CLOCK_ENTRY_TIME (entry1) < GST_CLOCK_ENTRY_TIME (entry2)) {
return -1;
}
return 0;
}
/**
* gst_clock_id_get_time:
* @id: The #GstClockID to query
*
* Get the time of the clock ID
*
* Returns: the time of the given clock id.
*
* MT safe.
*/
GstClockTime
gst_clock_id_get_time (GstClockID id)
{
g_return_val_if_fail (id != NULL, GST_CLOCK_TIME_NONE);
return GST_CLOCK_ENTRY_TIME ((GstClockEntry *) id);
}
/**
* gst_clock_id_wait:
* @id: The #GstClockID to wait on
* @jitter: (out) (allow-none): a pointer that will contain the jitter,
* can be %NULL.
*
* Perform a blocking wait on @id.
* @id should have been created with gst_clock_new_single_shot_id()
* or gst_clock_new_periodic_id() and should not have been unscheduled
* with a call to gst_clock_id_unschedule().
*
* If the @jitter argument is not %NULL and this function returns #GST_CLOCK_OK
* or #GST_CLOCK_EARLY, it will contain the difference
* against the clock and the time of @id when this method was
* called.
* Positive values indicate how late @id was relative to the clock
* (in which case this function will return #GST_CLOCK_EARLY).
* Negative values indicate how much time was spent waiting on the clock
* before this function returned.
*
* Returns: the result of the blocking wait. #GST_CLOCK_EARLY will be returned
* if the current clock time is past the time of @id, #GST_CLOCK_OK if
* @id was scheduled in time. #GST_CLOCK_UNSCHEDULED if @id was
* unscheduled with gst_clock_id_unschedule().
*
* MT safe.
*/
GstClockReturn
gst_clock_id_wait (GstClockID id, GstClockTimeDiff * jitter)
{
GstClockEntry *entry;
GstClock *clock;
GstClockReturn res;
GstClockTime requested;
GstClockClass *cclass;
g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
entry = (GstClockEntry *) id;
requested = GST_CLOCK_ENTRY_TIME (entry);
clock = GST_CLOCK_ENTRY_CLOCK (entry);
/* can't sync on invalid times */
if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
goto invalid_time;
cclass = GST_CLOCK_GET_CLASS (clock);
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "waiting on clock entry %p", id);
/* if we have a wait_jitter function, use that */
if (G_UNLIKELY (cclass->wait == NULL))
goto not_supported;
res = cclass->wait (clock, entry, jitter);
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
"done waiting entry %p, res: %d (%s)", id, res,
gst_clock_return_get_name (res));
if (entry->type == GST_CLOCK_ENTRY_PERIODIC)
entry->time = requested + entry->interval;
return res;
/* ERRORS */
invalid_time:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
"invalid time requested, returning _BADTIME");
return GST_CLOCK_BADTIME;
}
not_supported:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
return GST_CLOCK_UNSUPPORTED;
}
}
/**
* gst_clock_id_wait_async:
* @id: a #GstClockID to wait on
* @func: The callback function
* @user_data: User data passed in the callback
* @destroy_data: #GDestroyNotify for user_data
*
* Register a callback on the given #GstClockID @id with the given
* function and user_data. When passing a #GstClockID with an invalid
* time to this function, the callback will be called immediately
* with a time set to GST_CLOCK_TIME_NONE. The callback will
* be called when the time of @id has been reached.
*
* The callback @func can be invoked from any thread, either provided by the
* core or from a streaming thread. The application should be prepared for this.
*
* Returns: the result of the non blocking wait.
*
* MT safe.
*/
GstClockReturn
gst_clock_id_wait_async (GstClockID id,
GstClockCallback func, gpointer user_data, GDestroyNotify destroy_data)
{
GstClockEntry *entry;
GstClock *clock;
GstClockReturn res;
GstClockClass *cclass;
GstClockTime requested;
g_return_val_if_fail (id != NULL, GST_CLOCK_ERROR);
g_return_val_if_fail (func != NULL, GST_CLOCK_ERROR);
entry = (GstClockEntry *) id;
requested = GST_CLOCK_ENTRY_TIME (entry);
clock = GST_CLOCK_ENTRY_CLOCK (entry);
/* can't sync on invalid times */
if (G_UNLIKELY (!GST_CLOCK_TIME_IS_VALID (requested)))
goto invalid_time;
cclass = GST_CLOCK_GET_CLASS (clock);
if (G_UNLIKELY (cclass->wait_async == NULL))
goto not_supported;
entry->func = func;
entry->user_data = user_data;
entry->destroy_data = destroy_data;
res = cclass->wait_async (clock, entry);
return res;
/* ERRORS */
invalid_time:
{
(func) (clock, GST_CLOCK_TIME_NONE, id, user_data);
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
"invalid time requested, returning _BADTIME");
return GST_CLOCK_BADTIME;
}
not_supported:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "clock wait is not supported");
return GST_CLOCK_UNSUPPORTED;
}
}
/**
* gst_clock_id_unschedule:
* @id: The id to unschedule
*
* Cancel an outstanding request with @id. This can either
* be an outstanding async notification or a pending sync notification.
* After this call, @id cannot be used anymore to receive sync or
* async notifications, you need to create a new #GstClockID.
*
* MT safe.
*/
void
gst_clock_id_unschedule (GstClockID id)
{
GstClockEntry *entry;
GstClock *clock;
GstClockClass *cclass;
g_return_if_fail (id != NULL);
entry = (GstClockEntry *) id;
clock = entry->clock;
cclass = GST_CLOCK_GET_CLASS (clock);
if (G_LIKELY (cclass->unschedule))
cclass->unschedule (clock, entry);
}
/*
* GstClock abstract base class implementation
*/
#define gst_clock_parent_class parent_class
G_DEFINE_ABSTRACT_TYPE (GstClock, gst_clock, GST_TYPE_OBJECT);
static void
gst_clock_class_init (GstClockClass * klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->dispose = gst_clock_dispose;
gobject_class->finalize = gst_clock_finalize;
gobject_class->set_property = gst_clock_set_property;
gobject_class->get_property = gst_clock_get_property;
g_object_class_install_property (gobject_class, PROP_WINDOW_SIZE,
g_param_spec_int ("window-size", "Window size",
"The size of the window used to calculate rate and offset", 2, 1024,
DEFAULT_WINDOW_SIZE, G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_WINDOW_THRESHOLD,
g_param_spec_int ("window-threshold", "Window threshold",
"The threshold to start calculating rate and offset", 2, 1024,
DEFAULT_WINDOW_THRESHOLD,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_TIMEOUT,
g_param_spec_uint64 ("timeout", "Timeout",
"The amount of time, in nanoseconds, to sample master and slave clocks",
0, G_MAXUINT64, DEFAULT_TIMEOUT,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
/**
* GstClock::synced:
* @clock: the clock
* @synced: if the clock is synced now
*
* Signaled on clocks with GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC set once
* the clock is synchronized, or when it completely lost synchronization.
* This signal will not be emitted on clocks without the flag.
*
* This signal will be emitted from an arbitrary thread, most likely not
* the application's main thread.
*
* Since: 1.6
*/
gst_clock_signals[SIGNAL_SYNCED] =
g_signal_new ("synced", G_TYPE_FROM_CLASS (klass), G_SIGNAL_RUN_LAST,
0, NULL, NULL,
g_cclosure_marshal_generic, G_TYPE_NONE, 1, G_TYPE_BOOLEAN);
g_type_class_add_private (klass, sizeof (GstClockPrivate));
}
static void
gst_clock_init (GstClock * clock)
{
GstClockPrivate *priv;
clock->priv = priv =
G_TYPE_INSTANCE_GET_PRIVATE (clock, GST_TYPE_CLOCK, GstClockPrivate);
priv->last_time = 0;
priv->internal_calibration = 0;
priv->external_calibration = 0;
priv->rate_numerator = 1;
priv->rate_denominator = 1;
g_mutex_init (&priv->slave_lock);
g_cond_init (&priv->sync_cond);
priv->window_size = DEFAULT_WINDOW_SIZE;
priv->window_threshold = DEFAULT_WINDOW_THRESHOLD;
priv->filling = TRUE;
priv->time_index = 0;
priv->timeout = DEFAULT_TIMEOUT;
priv->times = g_new0 (GstClockTime, 4 * priv->window_size);
priv->times_temp = priv->times + 2 * priv->window_size;
}
static void
gst_clock_dispose (GObject * object)
{
GstClock *clock = GST_CLOCK (object);
GstClock **master_p;
GST_OBJECT_LOCK (clock);
master_p = &clock->priv->master;
gst_object_replace ((GstObject **) master_p, NULL);
GST_OBJECT_UNLOCK (clock);
G_OBJECT_CLASS (parent_class)->dispose (object);
}
static void
gst_clock_finalize (GObject * object)
{
GstClock *clock = GST_CLOCK (object);
GST_CLOCK_SLAVE_LOCK (clock);
if (clock->priv->clockid) {
gst_clock_id_unschedule (clock->priv->clockid);
gst_clock_id_unref (clock->priv->clockid);
clock->priv->clockid = NULL;
}
g_free (clock->priv->times);
clock->priv->times = NULL;
clock->priv->times_temp = NULL;
GST_CLOCK_SLAVE_UNLOCK (clock);
g_mutex_clear (&clock->priv->slave_lock);
g_cond_clear (&clock->priv->sync_cond);
G_OBJECT_CLASS (parent_class)->finalize (object);
}
/**
* gst_clock_set_resolution:
* @clock: a #GstClock
* @resolution: The resolution to set
*
* Set the accuracy of the clock. Some clocks have the possibility to operate
* with different accuracy at the expense of more resource usage. There is
* normally no need to change the default resolution of a clock. The resolution
* of a clock can only be changed if the clock has the
* #GST_CLOCK_FLAG_CAN_SET_RESOLUTION flag set.
*
* Returns: the new resolution of the clock.
*/
GstClockTime
gst_clock_set_resolution (GstClock * clock, GstClockTime resolution)
{
GstClockPrivate *priv;
GstClockClass *cclass;
g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
g_return_val_if_fail (resolution != 0, 0);
cclass = GST_CLOCK_GET_CLASS (clock);
priv = clock->priv;
if (cclass->change_resolution)
priv->resolution =
cclass->change_resolution (clock, priv->resolution, resolution);
return priv->resolution;
}
/**
* gst_clock_get_resolution:
* @clock: a #GstClock
*
* Get the accuracy of the clock. The accuracy of the clock is the granularity
* of the values returned by gst_clock_get_time().
*
* Returns: the resolution of the clock in units of #GstClockTime.
*
* MT safe.
*/
GstClockTime
gst_clock_get_resolution (GstClock * clock)
{
GstClockClass *cclass;
g_return_val_if_fail (GST_IS_CLOCK (clock), 0);
cclass = GST_CLOCK_GET_CLASS (clock);
if (cclass->get_resolution)
return cclass->get_resolution (clock);
return 1;
}
/* FIXME 2.0: Remove clock parameter below */
/**
* gst_clock_adjust_with_calibration:
* @clock: (allow-none): a #GstClock to use
* @internal_target: a clock time
* @cinternal: a reference internal time
* @cexternal: a reference external time
* @cnum: the numerator of the rate of the clock relative to its
* internal time
* @cdenom: the denominator of the rate of the clock
*
* Converts the given @internal_target clock time to the external time,
* using the passed calibration parameters. This function performs the
* same calculation as gst_clock_adjust_unlocked() when called using the
* current calibration parameters, but doesn't ensure a monotonically
* increasing result as gst_clock_adjust_unlocked() does.
*
* Note: The @clock parameter is unused and can be NULL
*
* Returns: the converted time of the clock.
*
* Since: 1.6
*/
GstClockTime
gst_clock_adjust_with_calibration (GstClock * clock,
GstClockTime internal_target, GstClockTime cinternal,
GstClockTime cexternal, GstClockTime cnum, GstClockTime cdenom)
{
GstClockTime ret;
/* avoid divide by 0 */
if (G_UNLIKELY (cdenom == 0))
cnum = cdenom = 1;
/* The formula is (internal - cinternal) * cnum / cdenom + cexternal
*
* Since we do math on unsigned 64-bit ints we have to special case for
* internal < cinternal to get the sign right. this case is not very common,
* though.
*/
if (G_LIKELY (internal_target >= cinternal)) {
ret = internal_target - cinternal;
ret = gst_util_uint64_scale (ret, cnum, cdenom);
ret += cexternal;
} else {
ret = cinternal - internal_target;
ret = gst_util_uint64_scale (ret, cnum, cdenom);
/* clamp to 0 */
if (G_LIKELY (cexternal > ret))
ret = cexternal - ret;
else
ret = 0;
}
return ret;
}
/**
* gst_clock_adjust_unlocked:
* @clock: a #GstClock to use
* @internal: a clock time
*
* Converts the given @internal clock time to the external time, adjusting for the
* rate and reference time set with gst_clock_set_calibration() and making sure
* that the returned time is increasing. This function should be called with the
* clock's OBJECT_LOCK held and is mainly used by clock subclasses.
*
* This function is the reverse of gst_clock_unadjust_unlocked().
*
* Returns: the converted time of the clock.
*/
GstClockTime
gst_clock_adjust_unlocked (GstClock * clock, GstClockTime internal)
{
GstClockTime ret, cinternal, cexternal, cnum, cdenom;
GstClockPrivate *priv = clock->priv;
/* get calibration values for readability */
cinternal = priv->internal_calibration;
cexternal = priv->external_calibration;
cnum = priv->rate_numerator;
cdenom = priv->rate_denominator;
ret =
gst_clock_adjust_with_calibration (clock, internal, cinternal, cexternal,
cnum, cdenom);
/* make sure the time is increasing */
priv->last_time = MAX (ret, priv->last_time);
return priv->last_time;
}
/* FIXME 2.0: Remove clock parameter below */
/**
* gst_clock_unadjust_with_calibration:
* @clock: (allow-none): a #GstClock to use
* @external_target: a clock time
* @cinternal: a reference internal time
* @cexternal: a reference external time
* @cnum: the numerator of the rate of the clock relative to its
* internal time
* @cdenom: the denominator of the rate of the clock
*
* Converts the given @external_target clock time to the internal time,
* using the passed calibration parameters. This function performs the
* same calculation as gst_clock_unadjust_unlocked() when called using the
* current calibration parameters.
*
* Note: The @clock parameter is unused and can be NULL
*
* Returns: the converted time of the clock.
*
* Since: 1.8
*/
GstClockTime
gst_clock_unadjust_with_calibration (GstClock * clock,
GstClockTime external_target, GstClockTime cinternal,
GstClockTime cexternal, GstClockTime cnum, GstClockTime cdenom)
{
GstClockTime ret;
/* avoid divide by 0 */
if (G_UNLIKELY (cnum == 0))
cnum = cdenom = 1;
/* The formula is (external - cexternal) * cdenom / cnum + cinternal */
if (G_LIKELY (external_target >= cexternal)) {
ret = external_target - cexternal;
ret = gst_util_uint64_scale (ret, cdenom, cnum);
ret += cinternal;
} else {
ret = cexternal - external_target;
ret = gst_util_uint64_scale (ret, cdenom, cnum);
if (G_LIKELY (cinternal > ret))
ret = cinternal - ret;
else
ret = 0;
}
return ret;
}
/**
* gst_clock_unadjust_unlocked:
* @clock: a #GstClock to use
* @external: an external clock time
*
* Converts the given @external clock time to the internal time of @clock,
* using the rate and reference time set with gst_clock_set_calibration().
* This function should be called with the clock's OBJECT_LOCK held and
* is mainly used by clock subclasses.
*
* This function is the reverse of gst_clock_adjust_unlocked().
*
* Returns: the internal time of the clock corresponding to @external.
*/
GstClockTime
gst_clock_unadjust_unlocked (GstClock * clock, GstClockTime external)
{
GstClockTime cinternal, cexternal, cnum, cdenom;
GstClockPrivate *priv = clock->priv;
/* get calibration values for readability */
cinternal = priv->internal_calibration;
cexternal = priv->external_calibration;
cnum = priv->rate_numerator;
cdenom = priv->rate_denominator;
return gst_clock_unadjust_with_calibration (clock, external, cinternal,
cexternal, cnum, cdenom);
}
/**
* gst_clock_get_internal_time:
* @clock: a #GstClock to query
*
* Gets the current internal time of the given clock. The time is returned
* unadjusted for the offset and the rate.
*
* Returns: the internal time of the clock. Or GST_CLOCK_TIME_NONE when
* given invalid input.
*
* MT safe.
*/
GstClockTime
gst_clock_get_internal_time (GstClock * clock)
{
GstClockTime ret;
GstClockClass *cclass;
g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
if (G_UNLIKELY (GST_OBJECT_FLAG_IS_SET (clock,
GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC) && !clock->priv->synced))
GST_CAT_WARNING_OBJECT (GST_CAT_CLOCK, clock,
"clock is not synchronized yet");
cclass = GST_CLOCK_GET_CLASS (clock);
if (G_UNLIKELY (cclass->get_internal_time == NULL))
goto not_supported;
ret = cclass->get_internal_time (clock);
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "internal time %" GST_TIME_FORMAT,
GST_TIME_ARGS (ret));
return ret;
/* ERRORS */
not_supported:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
"internal time not supported, return 0");
return G_GINT64_CONSTANT (0);
}
}
/**
* gst_clock_get_time:
* @clock: a #GstClock to query
*
* Gets the current time of the given clock. The time is always
* monotonically increasing and adjusted according to the current
* offset and rate.
*
* Returns: the time of the clock. Or GST_CLOCK_TIME_NONE when
* given invalid input.
*
* MT safe.
*/
GstClockTime
gst_clock_get_time (GstClock * clock)
{
GstClockTime ret;
gint seq;
g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
do {
/* reget the internal time when we retry to get the most current
* timevalue */
ret = gst_clock_get_internal_time (clock);
seq = read_seqbegin (clock);
/* this will scale for rate and offset */
ret = gst_clock_adjust_unlocked (clock, ret);
} while (read_seqretry (clock, seq));
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock, "adjusted time %" GST_TIME_FORMAT,
GST_TIME_ARGS (ret));
return ret;
}
/**
* gst_clock_set_calibration:
* @clock: a #GstClock to calibrate
* @internal: a reference internal time
* @external: a reference external time
* @rate_num: the numerator of the rate of the clock relative to its
* internal time
* @rate_denom: the denominator of the rate of the clock
*
* Adjusts the rate and time of @clock. A rate of 1/1 is the normal speed of
* the clock. Values bigger than 1/1 make the clock go faster.
*
* @internal and @external are calibration parameters that arrange that
* gst_clock_get_time() should have been @external at internal time @internal.
* This internal time should not be in the future; that is, it should be less
* than the value of gst_clock_get_internal_time() when this function is called.
*
* Subsequent calls to gst_clock_get_time() will return clock times computed as
* follows:
*
* |[
* time = (internal_time - internal) * rate_num / rate_denom + external
* ]|
*
* This formula is implemented in gst_clock_adjust_unlocked(). Of course, it
* tries to do the integer arithmetic as precisely as possible.
*
* Note that gst_clock_get_time() always returns increasing values so when you
* move the clock backwards, gst_clock_get_time() will report the previous value
* until the clock catches up.
*
* MT safe.
*/
void
gst_clock_set_calibration (GstClock * clock, GstClockTime internal, GstClockTime
external, GstClockTime rate_num, GstClockTime rate_denom)
{
GstClockPrivate *priv;
g_return_if_fail (GST_IS_CLOCK (clock));
g_return_if_fail (rate_num != GST_CLOCK_TIME_NONE);
g_return_if_fail (rate_denom > 0 && rate_denom != GST_CLOCK_TIME_NONE);
priv = clock->priv;
write_seqlock (clock);
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
"internal %" GST_TIME_FORMAT " external %" GST_TIME_FORMAT " %"
G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT " = %f", GST_TIME_ARGS (internal),
GST_TIME_ARGS (external), rate_num, rate_denom,
gst_guint64_to_gdouble (rate_num) / gst_guint64_to_gdouble (rate_denom));
priv->internal_calibration = internal;
priv->external_calibration = external;
priv->rate_numerator = rate_num;
priv->rate_denominator = rate_denom;
write_sequnlock (clock);
}
/**
* gst_clock_get_calibration:
* @clock: a #GstClock
* @internal: (out) (allow-none): a location to store the internal time
* @external: (out) (allow-none): a location to store the external time
* @rate_num: (out) (allow-none): a location to store the rate numerator
* @rate_denom: (out) (allow-none): a location to store the rate denominator
*
* Gets the internal rate and reference time of @clock. See
* gst_clock_set_calibration() for more information.
*
* @internal, @external, @rate_num, and @rate_denom can be left %NULL if the
* caller is not interested in the values.
*
* MT safe.
*/
void
gst_clock_get_calibration (GstClock * clock, GstClockTime * internal,
GstClockTime * external, GstClockTime * rate_num, GstClockTime * rate_denom)
{
gint seq;
GstClockPrivate *priv;
g_return_if_fail (GST_IS_CLOCK (clock));
priv = clock->priv;
do {
seq = read_seqbegin (clock);
if (rate_num)
*rate_num = priv->rate_numerator;
if (rate_denom)
*rate_denom = priv->rate_denominator;
if (external)
*external = priv->external_calibration;
if (internal)
*internal = priv->internal_calibration;
} while (read_seqretry (clock, seq));
}
/* will be called repeatedly to sample the master and slave clock
* to recalibrate the clock */
static gboolean
gst_clock_slave_callback (GstClock * master, GstClockTime time,
GstClockID id, GstClock * clock)
{
GstClockTime stime, mtime;
gdouble r_squared;
if (!gst_clock_is_synced (clock)) {
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
"Slave clock is not synced yet");
return TRUE;
}
stime = gst_clock_get_internal_time (clock);
mtime = gst_clock_get_time (master);
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
"master %" GST_TIME_FORMAT ", slave %" GST_TIME_FORMAT,
GST_TIME_ARGS (mtime), GST_TIME_ARGS (stime));
gst_clock_add_observation (clock, stime, mtime, &r_squared);
/* FIXME, we can use the r_squared value to adjust the timeout
* value of the clockid */
return TRUE;
}
/**
* gst_clock_set_master:
* @clock: a #GstClock
* @master: (allow-none): a master #GstClock
*
* Set @master as the master clock for @clock. @clock will be automatically
* calibrated so that gst_clock_get_time() reports the same time as the
* master clock.
*
* A clock provider that slaves its clock to a master can get the current
* calibration values with gst_clock_get_calibration().
*
* @master can be %NULL in which case @clock will not be slaved anymore. It will
* however keep reporting its time adjusted with the last configured rate
* and time offsets.
*
* Returns: %TRUE if the clock is capable of being slaved to a master clock.
* Trying to set a master on a clock without the
* #GST_CLOCK_FLAG_CAN_SET_MASTER flag will make this function return %FALSE.
*
* MT safe.
*/
gboolean
gst_clock_set_master (GstClock * clock, GstClock * master)
{
GstClock **master_p;
GstClockPrivate *priv;
g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
g_return_val_if_fail (master != clock, FALSE);
GST_OBJECT_LOCK (clock);
/* we always allow setting the master to NULL */
if (master && !GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_CAN_SET_MASTER))
goto not_supported;
if (master && !gst_clock_is_synced (master))
goto master_not_synced;
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
"slaving %p to master clock %p", clock, master);
GST_OBJECT_UNLOCK (clock);
priv = clock->priv;
GST_CLOCK_SLAVE_LOCK (clock);
if (priv->clockid) {
gst_clock_id_unschedule (priv->clockid);
gst_clock_id_unref (priv->clockid);
priv->clockid = NULL;
}
if (master) {
priv->filling = TRUE;
priv->time_index = 0;
/* use the master periodic id to schedule sampling and
* clock calibration. */
priv->clockid = gst_clock_new_periodic_id (master,
gst_clock_get_time (master), priv->timeout);
gst_clock_id_wait_async (priv->clockid,
(GstClockCallback) gst_clock_slave_callback,
gst_object_ref (clock), (GDestroyNotify) gst_object_unref);
}
GST_CLOCK_SLAVE_UNLOCK (clock);
GST_OBJECT_LOCK (clock);
master_p = &priv->master;
gst_object_replace ((GstObject **) master_p, (GstObject *) master);
GST_OBJECT_UNLOCK (clock);
return TRUE;
/* ERRORS */
not_supported:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, clock,
"cannot be slaved to a master clock");
GST_OBJECT_UNLOCK (clock);
return FALSE;
}
master_not_synced:
{
GST_CAT_DEBUG_OBJECT (GST_CAT_CLOCK, master,
"master clock is not synced yet");
GST_OBJECT_UNLOCK (clock);
return FALSE;
}
}
/**
* gst_clock_get_master:
* @clock: a #GstClock
*
* Get the master clock that @clock is slaved to or %NULL when the clock is
* not slaved to any master clock.
*
* Returns: (transfer full) (nullable): a master #GstClock or %NULL
* when this clock is not slaved to a master clock. Unref after
* usage.
*
* MT safe.
*/
GstClock *
gst_clock_get_master (GstClock * clock)
{
GstClock *result = NULL;
GstClockPrivate *priv;
g_return_val_if_fail (GST_IS_CLOCK (clock), NULL);
priv = clock->priv;
GST_OBJECT_LOCK (clock);
if (priv->master)
result = gst_object_ref (priv->master);
GST_OBJECT_UNLOCK (clock);
return result;
}
/**
* gst_clock_add_observation:
* @clock: a #GstClock
* @slave: a time on the slave
* @master: a time on the master
* @r_squared: (out): a pointer to hold the result
*
* The time @master of the master clock and the time @slave of the slave
* clock are added to the list of observations. If enough observations
* are available, a linear regression algorithm is run on the
* observations and @clock is recalibrated.
*
* If this functions returns %TRUE, @r_squared will contain the
* correlation coefficient of the interpolation. A value of 1.0
* means a perfect regression was performed. This value can
* be used to control the sampling frequency of the master and slave
* clocks.
*
* Returns: %TRUE if enough observations were added to run the
* regression algorithm.
*
* MT safe.
*/
gboolean
gst_clock_add_observation (GstClock * clock, GstClockTime slave,
GstClockTime master, gdouble * r_squared)
{
GstClockTime m_num, m_denom, b, xbase;
if (!gst_clock_add_observation_unapplied (clock, slave, master, r_squared,
&xbase, &b, &m_num, &m_denom))
return FALSE;
/* if we have a valid regression, adjust the clock */
gst_clock_set_calibration (clock, xbase, b, m_num, m_denom);
return TRUE;
}
/**
* gst_clock_add_observation_unapplied:
* @clock: a #GstClock
* @slave: a time on the slave
* @master: a time on the master
* @r_squared: (out): a pointer to hold the result
* @internal: (out) (allow-none): a location to store the internal time
* @external: (out) (allow-none): a location to store the external time
* @rate_num: (out) (allow-none): a location to store the rate numerator
* @rate_denom: (out) (allow-none): a location to store the rate denominator
*
* Add a clock observation to the internal slaving algorithm the same as
* gst_clock_add_observation(), and return the result of the master clock
* estimation, without updating the internal calibration.
*
* The caller can then take the results and call gst_clock_set_calibration()
* with the values, or some modified version of them.
*
* Since: 1.6
*/
gboolean
gst_clock_add_observation_unapplied (GstClock * clock, GstClockTime slave,
GstClockTime master, gdouble * r_squared,
GstClockTime * internal, GstClockTime * external,
GstClockTime * rate_num, GstClockTime * rate_denom)
{
GstClockTime m_num, m_denom, b, xbase;
GstClockPrivate *priv;
guint n;
g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
g_return_val_if_fail (r_squared != NULL, FALSE);
priv = clock->priv;
GST_CLOCK_SLAVE_LOCK (clock);
GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
"adding observation slave %" GST_TIME_FORMAT ", master %" GST_TIME_FORMAT,
GST_TIME_ARGS (slave), GST_TIME_ARGS (master));
priv->times[(2 * priv->time_index)] = slave;
priv->times[(2 * priv->time_index) + 1] = master;
priv->time_index++;
if (G_UNLIKELY (priv->time_index == priv->window_size)) {
priv->filling = FALSE;
priv->time_index = 0;
}
if (G_UNLIKELY (priv->filling && priv->time_index < priv->window_threshold))
goto filling;
n = priv->filling ? priv->time_index : priv->window_size;
if (!gst_calculate_linear_regression (priv->times, priv->times_temp, n,
&m_num, &m_denom, &b, &xbase, r_squared))
goto invalid;
GST_CLOCK_SLAVE_UNLOCK (clock);
GST_CAT_LOG_OBJECT (GST_CAT_CLOCK, clock,
"adjusting clock to m=%" G_GUINT64_FORMAT "/%" G_GUINT64_FORMAT ", b=%"
G_GUINT64_FORMAT " (rsquared=%g)", m_num, m_denom, b, *r_squared);
if (internal)
*internal = xbase;
if (external)
*external = b;
if (rate_num)
*rate_num = m_num;
if (rate_denom)
*rate_denom = m_denom;
return TRUE;
filling:
{
GST_CLOCK_SLAVE_UNLOCK (clock);
return FALSE;
}
invalid:
{
/* no valid regression has been done, ignore the result then */
GST_CLOCK_SLAVE_UNLOCK (clock);
return FALSE;
}
}
/**
* gst_clock_set_timeout:
* @clock: a #GstClock
* @timeout: a timeout
*
* Set the amount of time, in nanoseconds, to sample master and slave
* clocks
*/
void
gst_clock_set_timeout (GstClock * clock, GstClockTime timeout)
{
g_return_if_fail (GST_IS_CLOCK (clock));
GST_CLOCK_SLAVE_LOCK (clock);
clock->priv->timeout = timeout;
GST_CLOCK_SLAVE_UNLOCK (clock);
}
/**
* gst_clock_get_timeout:
* @clock: a #GstClock
*
* Get the amount of time that master and slave clocks are sampled.
*
* Returns: the interval between samples.
*/
GstClockTime
gst_clock_get_timeout (GstClock * clock)
{
GstClockTime result;
g_return_val_if_fail (GST_IS_CLOCK (clock), GST_CLOCK_TIME_NONE);
GST_CLOCK_SLAVE_LOCK (clock);
result = clock->priv->timeout;
GST_CLOCK_SLAVE_UNLOCK (clock);
return result;
}
static void
gst_clock_set_property (GObject * object, guint prop_id,
const GValue * value, GParamSpec * pspec)
{
GstClock *clock;
GstClockPrivate *priv;
clock = GST_CLOCK (object);
priv = clock->priv;
switch (prop_id) {
case PROP_WINDOW_SIZE:
GST_CLOCK_SLAVE_LOCK (clock);
priv->window_size = g_value_get_int (value);
priv->window_threshold = MIN (priv->window_threshold, priv->window_size);
priv->times = g_renew (GstClockTime, priv->times, 4 * priv->window_size);
priv->times_temp = priv->times + 2 * priv->window_size;
/* restart calibration */
priv->filling = TRUE;
priv->time_index = 0;
GST_CLOCK_SLAVE_UNLOCK (clock);
break;
case PROP_WINDOW_THRESHOLD:
GST_CLOCK_SLAVE_LOCK (clock);
priv->window_threshold = MIN (g_value_get_int (value), priv->window_size);
GST_CLOCK_SLAVE_UNLOCK (clock);
break;
case PROP_TIMEOUT:
gst_clock_set_timeout (clock, g_value_get_uint64 (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
gst_clock_get_property (GObject * object, guint prop_id,
GValue * value, GParamSpec * pspec)
{
GstClock *clock;
GstClockPrivate *priv;
clock = GST_CLOCK (object);
priv = clock->priv;
switch (prop_id) {
case PROP_WINDOW_SIZE:
GST_CLOCK_SLAVE_LOCK (clock);
g_value_set_int (value, priv->window_size);
GST_CLOCK_SLAVE_UNLOCK (clock);
break;
case PROP_WINDOW_THRESHOLD:
GST_CLOCK_SLAVE_LOCK (clock);
g_value_set_int (value, priv->window_threshold);
GST_CLOCK_SLAVE_UNLOCK (clock);
break;
case PROP_TIMEOUT:
g_value_set_uint64 (value, gst_clock_get_timeout (clock));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
/**
* gst_clock_wait_for_sync:
* @clock: a GstClock
* @timeout: timeout for waiting or %GST_CLOCK_TIME_NONE
*
* Waits until @clock is synced for reporting the current time. If @timeout
* is %GST_CLOCK_TIME_NONE it will wait forever, otherwise it will time out
* after @timeout nanoseconds.
*
* For asynchronous waiting, the GstClock::synced signal can be used.
*
* This returns immediately with TRUE if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
* is not set on the clock, or if the clock is already synced.
*
* Returns: %TRUE if waiting was successful, or %FALSE on timeout
*
* Since: 1.6
*/
gboolean
gst_clock_wait_for_sync (GstClock * clock, GstClockTime timeout)
{
gboolean timed_out = FALSE;
g_return_val_if_fail (GST_IS_CLOCK (clock), FALSE);
GST_OBJECT_LOCK (clock);
if (!GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC)
|| clock->priv->synced) {
GST_OBJECT_UNLOCK (clock);
return TRUE;
}
if (timeout != GST_CLOCK_TIME_NONE) {
gint64 end_time = g_get_monotonic_time () + gst_util_uint64_scale (timeout,
G_TIME_SPAN_SECOND, GST_SECOND);
while (!clock->priv->synced && !timed_out) {
timed_out =
!g_cond_wait_until (&clock->priv->sync_cond,
GST_OBJECT_GET_LOCK (clock), end_time);
}
} else {
timed_out = FALSE;
while (!clock->priv->synced) {
g_cond_wait (&clock->priv->sync_cond, GST_OBJECT_GET_LOCK (clock));
}
}
GST_OBJECT_UNLOCK (clock);
return !timed_out;
}
/**
* gst_clock_is_synced:
* @clock: a GstClock
*
* Checks if the clock is currently synced.
*
* This returns if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC is not set on the clock.
*
* Returns: %TRUE if the clock is currently synced
*
* Since: 1.6
*/
gboolean
gst_clock_is_synced (GstClock * clock)
{
g_return_val_if_fail (GST_IS_CLOCK (clock), TRUE);
return !GST_OBJECT_FLAG_IS_SET (clock, GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC)
|| clock->priv->synced;
}
/**
* gst_clock_set_synced:
* @clock: a GstClock
* @synced: if the clock is synced
*
* Sets @clock to synced and emits the GstClock::synced signal, and wakes up any
* thread waiting in gst_clock_wait_for_sync().
*
* This function must only be called if GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC
* is set on the clock, and is intended to be called by subclasses only.
*
* Since: 1.6
*/
void
gst_clock_set_synced (GstClock * clock, gboolean synced)
{
g_return_if_fail (GST_IS_CLOCK (clock));
g_return_if_fail (GST_OBJECT_FLAG_IS_SET (clock,
GST_CLOCK_FLAG_NEEDS_STARTUP_SYNC));
GST_OBJECT_LOCK (clock);
if (clock->priv->synced != ! !synced) {
clock->priv->synced = ! !synced;
g_cond_signal (&clock->priv->sync_cond);
GST_OBJECT_UNLOCK (clock);
g_signal_emit (clock, gst_clock_signals[SIGNAL_SYNCED], 0, ! !synced);
} else {
GST_OBJECT_UNLOCK (clock);
}
}